Spinoza reveals to us his fundamental ethical interest, which guides the whole of Spinoza's philosophy. I will take a brief look at part I of the Ethics, specifically with regard to his definition of God and Nature, and part II of the Ethics, with regard to the Mind or Soul, if you prefer. This journey is necessary so that the reader can better understand his extremely complex, yet very clear and distinct philosophy. As you might expect, in the course of the text we will make associations or disassociations with Cartesian philosophy, since Spinoza was an assiduous reader of René Descartes and evidently his philosophy has a Cartesian reference.